Vibrating meters such as, for example, densitometers, volumetric flow meters, and Coriolis flow meters are used for measuring one or more characteristics of substances, such as, for example, a density, a mass flow rate, a volume flow rate, a totalized mass flow, a temperature, and other information. Vibrating meters include one or more conduits, which may have a variety of shapes, such as, for example, straight, U-shaped, or irregular configurations. The measured fluid may comprise a liquid, a gas, or a combination thereof. The liquid may include suspended particulates.
The one or more conduits have a set of natural vibration modes, including, for example, simple bending, torsional, radial, and coupled modes. The one or more conduits are vibrated by at least one driver at a resonance frequency in one of these modes, hereinafter referred to as the drive mode, for purposes of determining a characteristic of the substance. One or more meter electronics transmit a sinusoidal drive signal to the at least one driver, which is typically a magnet/coil combination, with the magnet typically being affixed to the conduit and the coil being affixed to a mounting structure or to another conduit. The driver signal causes the driver to vibrate the one or more conduits at the drive frequency in the drive mode. For example, the driver signal may be a periodic electrical current transmitted to the coil.
One or more pick-offs detect the motion of the conduit(s) and generate a pick-off signal representative of the motion of the vibrating conduit(s). The pick-off is typically a magnet/coil combination, with the magnet typically being affixed to one conduit and the coil being affixed to a mounting structure or to another conduit. The pick-off signal is transmitted to the one or more electronics; and according to well-known principles, the pick-off signal may be used by the one or more electronics to determine a characteristic of the substance or adjust the driver signal, if necessary.
Positioning of the driver as well as the pick-offs is typically performed on an alignment tool assembly with various alignment blocks. The alignment blocks can slide into place and hold mounting brackets that are used to couple the driver and pick-offs to the vibrating meter's tubes. In order to achieve optimum performance out of the vibrating meter, the precise positioning of the driver and pick-offs, and thus, the brackets is important. For example, the distance between the pick-offs may be critical to optimum operation of the vibrating meter. While the alignment tool assembly originally provides the necessary positioning, over time, the alignment blocks can move out of proper alignment due to wear, damage, etc. Therefore, the prior art periodically takes the alignment tool assembly out of production to perform maintenance, including ensuring proper positioning of the alignment pieces. Unfortunately, taking the alignment tool assembly off-line results in a downtime in production.
Therefore, there is a need in the art for a system that can quickly and accurately ensure the correct positioning of the alignment pieces of the alignment tool assembly. There is a need in the art for a system that can ensure the positioning of the alignment pieces without having to move the alignment tool assembly to a specialized testing facility.
The embodiments described below overcome these and other problems and an advance in the art is achieved. The embodiments described below provide an alignment tool assembly with gauge apertures formed in the alignment tool assembly's mounting plate that can accept alignment gauges in order to test the positioning of one or more alignment blocks. The alignment gauges allows the alignment tool assembly to be tested quickly without moving the alignment tool assembly to a specialized testing area.